Differential feeding mechanism



April 21, 1925 J. R. MOFFATT DIFFERENTIAL FEEDING MECHANISM Filed 001;. 20, 1921 3 Sheets-Sheet 1 April 21, 1925.

J. R. MOFFATT DIFFERENTIAL FEEDING MECHANISM Filed Oct. 20, 1921 3 Sheets-Sheet 2 April 21, 1925. 1,534,132

J. R. MOFFATT DIFFERENTIAL FEEDING MECHANISM Filed Oct. 2 1921 3 Sheets-Sheet 5 tively' Patented Apr. 21, 1925.

JAMES E. MOFZ AT Oil CHIGAGO, ILLINOIS, ASSIGNOB 'IO UNION SPEGLELL l.

E N E GOMPANY,1OF CHICAGO, ILLINOIS, A COR-ECRATION-OFILLINOIS.

DIFFERENTIAL FEEDING IlIECE-IANISM.

Application filed Gotcha-'20,; 1921.

To all whom it may concern:

Be it known that I, JAMES R. Morrnrr, a. citizen of the United gtet es, residing at Uhicago, in the county of Cook, State of Illinois, have invented certain new and useful Improvements in Differential Feeding ll'lfsfillitl'llSlllS, 01"- which the following is a description, reference being had to the accompanying drawing, and to thefigures of reference marked thereon.

The invention relate to new and useful improvements in differential feeding mecha- 1llS11S for sewing machines, and more particularly differential feeding mechanism which is adapted to he used in a coniperm smallxw-ork. supporting arr i An object of theinvention is to provide a differential feeding mechanism for a work supporting arm which isso constructed that the feed dog may be raised and lowered Jii h little .or no tilting of the feed dog from front or reer or vice'versa.

further object of the invention is to provide differential feeding mechanism of the shove character, wherein the auxiliary feed her is supported by a main feed her,

so as to move up end down therewith and wherein said main ieed her extends substantielly the entire length of. the work supgorting arm and ispivotallv and. slidably supported at the inner endithereotf, so that the swinging movements" of the feed her to raise andilower the feed: dogs will! cause said teed dogs to move bodily vertically with little or no tilting. of the feed dogs from front to rear or vice verse.

A further object of the invent-ion is to provide a dillerentiel feeding inechanismot' the above type wherein the work engaging movements of the-teed dogs entlthe feeding in rein-elite oi the feed dogsaresecured from two levers iulcrumed in: the worlr' supporting arm and extending to points within a vertical frame member carrying the work supporting arm s'othateccentriostraps in said vertical frame membermay be connected to and operate said levers.

These and other objects will in; parhhe obvious and will in part he lieneinait'er'more lolly disclosed.

In the drawings which show by way of liustration one embodiment of the inven- Serial No. 508,931.

a port-ion ot a sewing machine with mv inproved diilerent-ia-l feeding mechanism embodied therein;

the vertical frame member is mounted;

Figure a perspective view of the-main feed bar, the bracket which pivota-lly and slidahly supports the same rind the pivot pin the parts being separated to more clearly show the structure; I

Figure is a sec ionalview on the 4ti of l;

Figure 5 is a sectional view on the line of Fig. l;

Figure- 6v is a sectional view on the 6+6 of Fig. 1;

Figure 7 is a perspective view or the-lever for raising and lowering the main feed bar end: the fulcrum pin therefor, said pin being separated from the lever to show the eccentric construction for shitting the positionolfthe fulcrum of the lever;

Figuretl isa perspective view of the lever for moving tho feed her back one forth;

Figure'tl is a perspective view of the aura isry feed her and: the lever which moves some back. and forth.

Iheve shown the invention {is-applied to line line

s sewing machine of the type discloscd in the patent granted to Lansing; @nderdonl; December 18, 1906; No. 839,077. Said machine has a frame member extending horizontally andv parallel with the overhanging arm. The machine hesbeen illustrated only in'part in the drewiirqsand-reference should he had to said patent for a better understanding of the complete machine.

In the present drawings the horizontally extending member referred to is indicated at l and in said horizontally extending member is an operating shaft 2 which is driven through suitable conn ctions from the main shaft. Projecting vertically from the horizontally projecting frame inemher l is vertical frame member 3. The shalt 2 projects into the vertical frame member 3 and the end thereof men" in a bracket 42. Formed the vertical frame member 3 r supporting arm 5 w'iich is relati Sil'll'll, and which projects laterally said vertical frame member to a underneath the needles. The needles are indicated at 6 in the drawings and are carried by a needle bar 7. (lo-operating with the needles 6 is a threadlooper 8 which is carried by a looper shaft 9. Said looper shaft 9 is mounted in suitable hearings in the work supporting arm 5 and the vertical frame member 3, so that the shaft may be oscillated and also moved endwise for giving the proper movements to the loop-er. The looper supporting shaft 9 is oscillated by means of a link 10 which is connected to a radial arm 11 fixed to the looper supporting shaft 9. This link 10 at its lower end is connected to one arm of a rock lever 12,

' which is pivoted at 13 to the vertical frame member 3. The

1 connected to a collar 21 free on the looper shaft and located between spaced cellars 22-22 attached to the looper shaft. As this rock lever 19 is oscillated the looper supporting shaft is moved endwise and as the link 1 1 and arm 16 which form toggle links are moved toward and from a center line the looper is moved into and out of the needle thread loop and a dwell is given to the oscillation of the looper at the forward end of its stroke. This looper mechanism which has been referred to briefly forms no part of the present invention but is shown, described and claimed in my co-pending application filed of even date herewith.

The material being stitched is helc on the work support by a presser foot shown diagrammatically and in broken lines at 23 in the drawings. The material is fed off from the end of the arm as it is stitched and this is brought about by two feed dogs-the main feeddog 24 and'anauxilia'ry feed dog The main feed dog 2 1 is carried by a main feed bar 26 which extends lengthwise of the work supporting arm 5. Said feed bar 26 at its rear end carries a pivot pin 27 which is located in the openings 28 in the feed bar. The bracket 29 carried by the work supporting frame is slotted at 80. The pivot pin EZY-has a reduced section 31 which is adapted to fit in this slot 30 and slide back and forth therein. A screw 32 passes down through the bracket andcloses the slot- 30. Through this construct-ion the feed bar is capable of being moved endwise as the pin slides in the slot. It may also be raiseo and lowered atits free end, said bar turning freely on the cylindrical ends of tne pivot pin 27. The main feed dog is secured to the main feed bar by ascrew 33, see Fig. 1. The main feed bar is moved endwise for imparting feeding movements to the feed dog 2ft by means of a lever 3 1. Said lever 3 1 is shown more in detail in Fig. 8 and consists of a central sleeve 35, a rearwardly projecting arm 36 and a forwardly projecting arm 3?. Said last named arm is provided with a curved slot 38. The sleeve 85, clearly shown in Fig. 6 of the drawings, is mounted on a pin 39 which is secured in the work supporting arm by means of a set screw 10. The lever rocks freely on this pin. The rear ly connected to an eccentric strap 11 which co-c-perates with an eccentric on the main shaft;

iidjustably mounted in the slot 38 is a tud A link 1-3 is pivotally connected 2 rotates the eccentric strap 411 will rock the lever Said lever as it rocks will give an endwise movement to the link 43 and this will impart an endwisemovement to the feed bar 26. By adjusting the position of the stud +12 the extent of movement imparted to the main feed bar may be varied.

The main feed bar is raised and lowered by means of a lever 1-5. in perspective in Fig. 7 of the drawings. The lever is provided with a sleeve 46 having an opening 47 through which a pivot pin 48 extends. This pivot pin 18 has an eccentric section 49 and a slotted head 50. The slotted head is cut away on one side, as indicated at 51. When the pin is in place, the eccentric section 419 is located in the sleeve 16. This pivot pin is mounted in bearing lugs 5252 carried by the work supporting arm 5. A set screw 53 passes down through the top ofone of the lugs and into the cut away portion 51 and is adapted to clamp the pivot pin against movement. By loosening this set screw a suitable tool may be placed in the slot of the head 50, and the pivot pin turned so as to shift the position of the eccentricsection 19 and this will raise or lower-the fulcrum axis of the lever 15. The lever 15 at its forward end is conneeted to two spaced links 5el54. These spaced links 5=154t are arr nged on opposite sides of the forward end of the lever and are secured thereto by a pivot pin The links at their upper end are secured to the feed bar by a pivot pin 56. The lever 15 is connected at its rear end to an eccentric strap 57 which co-operates with an eccentric on the shaft- 2. its the shaft 2 rotates the lever 15 will be oscillated and this will raise end of the lever 3 1 is pivotal- 0 this stud at its forward end, and this link.

Said lever is shown and lower the main feed bar. By shifting the position of the eccentric portion 49 the fulcrum of the lever l5 may be raised and lowered and thus the woiaking position of said lever varied and this will vary the position of the up and down movements of the feed bar, and the feed :dog carried thereby.

, The feed bar 26 is provided wi h a longitudinal slot 58 in theupper face thereof. liounted in said slot is an auxiliary, feed bar 59 to which the auxiliary feed dog is secured by means of a screw 60. Attached to the main feed bar is an angle plate 61. Said plate is secured to the feed bar by means of screws 6262 and is so'positioned as to overlap the auxiliary feed bar 59 and this plate confines the auxiliary feed bar to endwise movements only relative to the main feed bar. All up and down movements of the main feed bar are imparted to this auxiliary feed bar 59.

The auxiliary feed bar 59 is moved back and forth by means of a lever 63. This lever 63 is shown in perspective View in Fig.

9. Saidlever 63 is provided with a projecting sleeve 64 at its upper end. Said sleeve isv located in a cut-away portion 65 in the feed bar, see Figs. 1, 3 and 5. A pivot screw 66 extends through the sleeve and is threaded into the auxiliary feed bar so that the lever is thus pivotally connected to the auxiliary feed bar. Thelever at its lower end carries spaced arms 67-67, which extend downat each side of the forward portion of the lever 45. Each arm is forked at 68. The lever 45 carries pins 69-69, one at each side of the lever and these forked ends of the lever 63 engage over said pins 6969. These pins actas fulcrum for the lever 63. Said lever is also provided with a segmental slot 70. A link 71 is pivoted at its forward end to a stud 72, adiustably mounted in the slot 70. T ieother'end of this link 71 is pivoted at 73 to the mainfeed bar.

As the main feed bar moves back and forth it will oscillate the lever 63, swinging the same about the'fulcrum pin 69. This is accomplished through the link connection Inasmuch as the lever 63 is connected to the auxiliary feed bar it will move the auxiliary feed bar endwise on the main feed bar provided the stud 72 is below a line passing through the pivot bolt 66 and the pivot pin 73. Tn other words, the distance from the stud 72 to the fulcrum 69 is less than the distance from the pivot pin 66 to said fulcrum 69. This movement of the auxiliary feed bar on the main feed bar can, of course, be increased by lowering the stud T2 in the slot 76. Thus it is that a different movement can be imparted to the auxiliary feed dog from that which is imparted to the main feed dog and this constitutes what is well-known in the art as a differential feeding mechanism. The auxiliary feed dog moves the fabric to a greater extent than the main feed dog and thus it is fulled in in front of the needles as the stitching goes on.

From the. above description, it will be apparent that I have provided a very simple differential feeding mechanism, which consists of very few parts andwherein both the main feed dog and the auxiliary feed dog are operated from the same two eccentrics and at the same time a differential feeding movement is given to the different dogs. Then, again, it will be apparent that, I'have packed my entire feeding mechanism in the work supporting arm and the various movements are imparted to the feed dogs from two levers projecting rearwardly into the vertical frame member where they may be readily connected to cocentric straps and operated from rotating eccentrics at the lower end of the vertical frame member.

It is obvious that minor changes in the details of construction and the arrangement of the parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus described my invention, what I claim asnew and desire to secure by Letters Patent, is:

1. The combination with a vertically extending frame member, work supporting armiat the upper end thereof projecting laterally therefrom, an operating shaft extending into said frame member, a main feed dog, a main feed bar extending lengthwise of the work supporting arnland terminating adjacent said frame member, means for moving said feed bar back and forth including a lever pivoted to the work supporting arm along side of said main feed bar and extending into the vertically extending rame member, devices actuated by the operating shaft for oscillating said lever, a link connected with the lever at a point intermediate the ends of the main feed bar and extending rearwardly and pivotally connectcd to the rear end of the main feed bar, and means for raising and lowering said main feed bar.

inc

2. The combination of a ver cally entend- 7 ing frame member, a work supporting arm at the upper end thereof projecting laterally therefrom, an operating shaft extending into said frame member, a main feed dog, a main feed bar extending l ngthwise of the work supporting arm and terminating adjacent said frame member, an auxiliary feed dog, an auxiliary feed bar supported by said main feed bar and carrying said auxiliary feed dog, means for moving vthe feed bars back and forth including a lever pivoted in the work supporting arm alongside of the main feed bar and extending into the vertical frame membeiydevices actuated by the operating shaft for oscillating said lever, a link connected with the lever at a point intermediate the ends of the main feed bar and extending rearwardly and pivotally connected to the rear end of the main feed bar, devices for imparting a difierential movement to the auxiliary feed dog from said main feed bar, and means for raising and lowering said feed dogs.

3. The combination with a vertically ex-- tending frame member, a work supporting arm locatedat the upper end thereof and projecting laterally therefrom, an operating shaft extending lengthwise of the work supporting arm and terminating adjacent the dogs, said lever extending into said vertical member, means for operating said lever from said shaft, a second lever located alongside of said main feed member and extending into said vertical member, means for oscillating said second lever from said shaft,

a link having adjustable connection with the outer end of said lever and with the feed bar at the extreme inner [end thereof for moving the feed her back and forth, and means for imparting a differential movement to the auxiliary feed dog from said main feed bar. I

d. The combination with a vertically extending frame member, a work supporting arm located at the upper end thereof and projecting laterally therefrom, an operating shaft extending into said frame member, a main feed bar extending lengthwise of said arm and terminating adjacent the work sup porting 'member, means for pivotally sup porting the inner end of said feed barrwherebythe same may slide back and forth, a lever located in said arm alongside of the feed bar and extending rcarwardly into said vertical member, meansfor oscillating said lever from said shaft, a link having adjust- V able connection with the outer end' of said lever and the inner end of said feed bar adjacent the pivot therefor, an auxiliary feed dog carried by said main food bar and movable up and down therewith, means for giving said auxiliary feed dog a differential movement from said main feed bar, a second lever located in said arm alongside of said main feed bar and projecting rearwardly into said vertical member, means for operating said lever from said shaft, and a pair of links connected with the after end of said last-named lever and with the main feed bar for raising andlowering the same.

5. The combination with a vertically extending frame member, a work supporting arm located at theupper end thereof, and projecting laterally therefrom, an operating shaft extending into said frame member, a main feed bar extending lengthwise of said arm and terminating adjacent the work supporting member, means for pivotally sup porting the inner end of said feed bar whereby the same may slide back and forth,

a lever locatedin said arm alongside of the feed bar and extending rearwardly into said vertical member, means for oscillating said lever from said shaft, a link having adjuso able connection with the outer end of said lever and the inner end of said feed bar adjacent the pivot therefor, an auxiliary feed dog carried by said main feed bar and movable up and down therewith, means for giving said auxiliary feed dog a differential movement from said main feed bar, a second lever located in said arm alongside of said .main feed bar and projecting rearwardly "arm located at the upper end thereof and projecting laterally therefrom, an operating shaft extending into said frame member, a main feed bar extending lengthwise of said arm, a main feed dog carried thereby, an auxiliary feed bar supported by the main feed bar, an auxiliary feed dog carried by aid auxiliary feed bar, means operated from said shaft for raising and'lowering said feed bars, means operated from said shaft for moving said main feed bar back and forth, a lever pivotally connected at its upper end to said auxiliary feed bar, a link having an adjustable oonitieot-ion withsaid lever and connected to said main feedbar, said lever at the lower end thereof being forked, and a fulcrum pin extending througl'i said forked end of the lever whereby said lever may rock on said fulcrum pin and impart feedlng movements to the auxiliary feed dog, and may move up and down on the fulcrum pin with the up and down movements of the auxiliary feed bar.

7. The combination of a vertically extending frame'member, a work supporting arm projecting laterally therefrom, an op erating shaft extending into said frame member, a main feed dog, a feed bar carrying said main .feed dog and extending lengthwise of said arm, means for pivotally and slidably supporting the inner end of said feed bar, said pivot being located at the inner end of said arm, an auxiliary feed dog, an auxiliary feed bar carried by said main feed bar, and movable up and down therewith, means for raising and lowering the feed bars, means for moving said main feed bar back and forth including a lever pivoted in said work supporting arm and extending alongside of said main feed bar into said vertically extending frame member, a link pivoted to said lever and to the feet bar at its inner end, devices actuated by the operatingslmft and connected to said lever for oscillating; the lover, a second lever coir nected to said auxiliary feed bar, and means for connecting said second lever to the main feed bar, whereby movements of different extent may be imparted to said auxiliary feed bar from said main feed ba 8. The combination of a vertically extending frame member, a work supporting arm projecting laterally therefrom, an operating shaft extending into said frame member, a main feed dog, a feed bar carrying said main feed dog and extending lengthwise of said arm, means for pivotally and slidably supporting the inner end of said feed bar, an au'iliary feed dog, an auxiliary feet bar czrried by the main feed bar and movable up and down therewith, means for raising and lowering the feed bars, means for movin;- said main feed bar back and forth including a lever pivoted in said work supporting arm and extending into said vertical frame member, an eccentric on the operating shaft, an eccentric strap co-operating therewith and connected to said lever for oscillating said lever, said lever having a slotted arm, a link having an adjustable connection with said slotted arm and said main feed bar for moving said main feed bar back and forth, a second lever pivoted to said auxiliary feed bar, said second lever having a slotted portion, a link adjustably connected to said slotted portion and to the main feed bar for oscillating the lever connected to said auxiliary feed bar, and means for pivotally supporting said last named lever.

9. The combination of a vertically extending frame member, a work supporting arm projecting laterally therefrom, an operating shaft extending into said frame member, a main feed dog, a feed bar carrying said main feed dog and extending lengthwise of said arm, means for pivotally and slidably supporting the inner end of said feed bar, an auxiliary feed dog, an auxiliary feed bar carried by the main feed bar and movable up and down therewith, means for raising and lowering the feed bars including a lever pivoted in said work supporting arm and extending underneath the main feed bar, a pair of links connecting one end of said lever with the main feed bar, said lever at its other end extending into said vertical frame member, an eccentric strap connected thereto, an eccentric on said operating shaft with which said strap co-operates, means for moving said main feed bar back and forth including a lever pivoted in said work supporting arm and having one end thereof slotted, a link adjustably ccnnected'to said slotted end and to the main feed bar for moving it back and forth, the other end of said lever extending into said vertical frame member, an eccentric strap connected thereto and an eccentric on said operating shaft for operatingsaid c "t named eccentric strap, a third lever in ,z d work supporting arnrhaving slotted spaced arms straddling the lever for raising and lowering the feed bar, pins carried by said lever and engaging said fork d arms and forming a fulcrum for the lever, said lever being connected to the auxiliary feed bar and having a slotted portion, and a link adjustably connected to said slotted portion at one end and at its other end to said auxlliary feed bar.

in testimony whereof, I aflix my signature.

JAMES B. MOFFATT, 

